1. Field of the Invention
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for measuring signals of peripheral cells when heterogeneous wireless communication modules coexist in a terminal and an apparatus thereof.
2. Description of the Related Art
In recent years, with the increasing use of smart phones, demand and use of wireless Local Area Networks (LANs), Bluetooth, and Global Positioning Systems (GPS) have rapidly increased. According to the trend, various heterogeneous communication technologies such as a conventional cellular network technology (i.e., Long Term Evolution/Universal Mobile Telecommunications System (LTE/UMTS)), wireless LAN and Bluetooth, and Global Navigation Satellite System (GNSS)/GPS frequently coexist. When the heterogeneous communication technologies are simultaneously used, there arises a mutual interference problem. With respect to the issue, In-Device Coexistence (IDC) has been discussed in the 3rd Generation Partnership Project (3GPP) standards setting. A heterogeneous communication technology other than LTE refers to an interfering Communication Technology (CT).
For example, LTE/UMTS communication technology operates at various frequency bands, whereas a communication technology such as Bluetooth or wireless LAN operates at an Industrial, Scientific and Medical (ISM) band of 2400˜2483.5 MHz. In particular, among various bands using the LTE/UMTS communication technology, because Band 4 (2300-2400 MHz) and uplink band (2500-2570 MHz) of Band 7 are adjacent to an ISM band used by the Bluetooth and the wireless LAN, when they are simultaneously used, a transmission signal in one communication technology may be treated as a received signal in another communication technology which causes strong interference.
In the meantime, for a general report with respect to signal quality, when signal qualities of peripheral cells are better than that of a cell (referred to as ‘serving cell’ hereinafter) with which a terminal is communicating, the terminal reports this condition to the cell. However, when signals of peripheral cells are simultaneously deteriorated, the terminal does not report measured information to the cell. When such a situation occurs, it is difficult for the terminal to communicate with the cell and cannot receive other processes (e.g., handover command to another cell, etc.). Therefore, a need exists for an improved apparatus and method for measuring signals of peripheral cells when heterogeneous wireless communication modules coexist in a terminal.